Device for preparing piano skeleton frames



H- WILLIAMS DEVICE FOR PREPARING PIANO SKELETON FRAMES Filed June 9 1925 4 4 Sheets-sh 1 mmnummml mun Nov. 23 1926. 1,608,452

J. H. WILLIAMS DEVICE FOR PREPARING PIANO SKELETON FRAMES Filed June 9 5 4 Sheets-Sheet :5

\\ mill muw/// ll 11 k Nov. 23 1926. I 1,608,452

' J. H. WILLIAMS DEVICE FORPREPARING PIANO SKELETON FRAMES gnmwfoz I v JHJVii/z'ama Patented Nov. a3, 1926.

srArss PATENT OFFHCE.

JAMES Iii. VIILLIAMS, OF NOB-WALK, OHIO, lafisIG-ii'oE To UNITED YIANO (703F031.

TION, OF NORWALH, OHIO, A

CQRPORATEOII OF NEW YORK.

DEVICE FOR PREPARING PIANO SKELETON FBATIZES.

Application filed June 9.

This invention relates to pianos, and particularly to the manufacture of skeleton frames to which the sounding-boards are attached.

In the manufacture of sounding-boards for grand pianos, the boards are arched or crowned across their major and minor di mensions, and ribs are secured to the concaved or under faces thereof. The soundingboards are then glued, at their edge portions to tl e upper faces of substantially U- shaped skeleton frames. In order to facilitate the assembly of a sounding-boardand this skeleton frame, and to insure a proper fit between the edge portions of the board, as well as the end portions of the ribs thereof, and upper face of this skeleton frame, it is necessary to so bevel the upper face of the skeleton frame, or trim such face on such a slope that it will properly conform to the edges of the arch or crown of the soundingboard. Furthermore, it is also necessary to provide grooves or channels in the upper face of the skeleton frame to receive the end portions of the ribs of the sounding-boards.

Heretofore, this beveling and channeling of the skeleton frame has been accomplished by means of hand saws, chisels, and hand planes, with the result that a large amount of time and labor have been consumed, and the resultant finished product more or less inaccurate.

It is therefore, the principal object of the present invention to provide means for quickly and accurately trimming the upper marginal edge of the skeleton frame to in sure a perfectand continuous fit with the margin of the sounding-board, and to provide means for accurately channeling the trimmed edge at exact diametrically opposite points snugly receive the rib ends.

Another object is to provide means for forming the channels of one portion of the skeleton frame in direct alinement with those at the opposite side thereof, whereby the opposite ends ofthe ribs of the sounding-board will readily and accurately seat themselves in such channels without danger of springing the ribs or the sounding-board.

It further object is to provide a form for receiving a SOlUltllllQ-bOt-tfll skeleton frame which is of such construction that the depth and width of the rib receivin channels as well as the angle of the bottom walls thereof,

will be accurately formed to snugly receive 1925. Serial No. 35,960.

the end portions of the ribs of the sounding board. 7

A. further object is to provide a form for the skeleton frame of grand piano which includes means for permitting the proper disposition of the frame in the form, without interference of the braces of the frame.

Other objects and advantages will be apparent from the following description when taken in connection with the accompanying drawings.

In the drawings:

Figure l is a plan view of a form in which is disposed the skeleton frame to be beveled and channeled, a portion of the removable wall 20 being broken away.

Figure 2 is a sectional view, on the line 22 of Figure 1.

Figure 3 is a transverse sectional view on the line 3-3 of Figure 1.

Figure l is an enlarged transverse sec tional detail view on line a -l of Figure 1.

Figure 5 is a perspective view of a skeleton frame, one portion of which shows the frame before being beveled and channeled, while the remaining portion shows the same after having been beveled and channeled.

Figure 6 is a fragmentary perspective view of a portion of the form, showing means for holding the skeleton frame therein.

Figure 7 is an enlarged elevation of a por tion of the form showing the gate or door.

Figure 8 is a perspective view of the removable wall. 20.

Figure 9 is a plan view of the planer for forming the bevel on the upper edge face of the skeleton frame.

Figure 10 is an end elevation of the planer. Figure 11 is a plan view of the sawing device for forming tie rib receiving grooves in the skeleton frame.

Figure 12 is a side elevation of the sawing device. Referring particularly to the accompanying drawings, the form, which is supported on the legs A, has an outline corresponding to that of the skeleton frame of a grand piano, said form being composed of the par allel side portions 10, connected atone end to the curved portion 11. The form has a longitudinal channel 13 extending throughout the length thereof forthe reception of the skeleton frame of a grandpiano. The inner walls 10, of the form, are slightly higher than the outer walls, and both of said (all ' the portion 11.

are the pivoted'bolts 2 3, which are adapted distance above the brace 16,

walls have their upper edges beveled downwardly and outwardly in a common plane, as clearly seen in Figure 3. The inner walls of the free ends of the side portions 10 are connected by the transverse wall 12,

while portions of said inner walls adjacent the curved portion, are cut out to form the openings, indicated by the numeral 13 which lead into the said channel 13. Disposed in parallel relation to the wall 12 is a removable wall 20, to which more particular reference will be made later herein.

Figure 5 shows a perspective view of the skeleton frame, which comprises the leg portions 14, the connecting curved bight portion 15, the transverse brace 16, extending between and connected to the leg portions 14, and having the depending aron 16', ant the braces 1'? which radiate from the intermediate portion of thebrace 16, and are connected at their outer ends to the inner face of the curved portion 15. This frame is arranged tobe placed in the channeled form, with its different portions seated within the corresponding portions of the form. To permit proper disposition of the skeleton frame in the channel 13, provision mustbe made for the outer ends of the braces 17 to 7 pass the inner walls of the form. Such provisionis made by forming openings 18 and 19 in the inner walls of the curved portion 11, of the form. The ends of the transverse race 16 pass through the openings 13 of the side walls 10. the transverse brace 16 is of greater width than the distance between the walls 12 and 20, and to permit this brace to be seated in the form, the inner wall 20 of this portion of the form is rendered removable, and has its opposite ends extended in a common direction and plane, to meet the ends of the inner walls 10 inwardly of the cut-awa ,"s 13. Carried by these ends of the wall 20, and extending longitudinally of the inner-faces of the said inner walls of the portion 11, are the blocks 21, which, when the wall 20 is properlypositioned, overlie the blocks 22, carried by the inner face of Carried by the blocks 21 to swing downwardly into grooves 24, in

the said blocks, and grooves 25,-in the blocks 22, winged nuts 28 being engaged on the free ends of the bolts for engagement with the lower fac s of the blocks 22, to retain the wall 20 in proper position. In view of the fact that the wall 20 is spaced a short it is necessary sagging under tool, to which Carto support this wall against the we 'ht of the groov ng referencewill be made later herein.

,nea by'the inner vertical face of the wall 20 is a bloclr26 through. which is threadeda screw 1 the head of which is arranged'to V provided with a transverse handle 27, for turning the screw.

Hinged to the upper portion of each of the openings 18 and 19 is a gate 28, having a suitable latch 29 for holding the same in closed position over'the end of one of the braces 17, where said brace passes through the opening, said door serving to prevent up- Wi lICl movement of the skeleton frame within the form as will be understood. Bridging the lower sides of the openings 18 and 19, and secured to the lower face of the bot tom of the channel 18, are the U-shaped braces 30.

Formedtransversely through the upper edges of the side walls of the form, i re the grooved channels 31, those at one side of the form being in direct alignment with those at the opposite side thereof, as clearly seen in the plan view, Figure 1, and the botends of the transverse brace 16 for holding said frame tightly on the supporting strip 11, which rests on the bottom of the channel 13. Secured to the lower face of the bottom wall of the channel 13, in spaced relation. thereto, and below the openings 13 of the side walls 10, are the ends of the transverse brace 44. Disposed for vertical slidable movement in a vertical groove 45, in the inner wall of the form adjacent the inner face of the brace 16, is a rod 46, said rod having a longitudinal slot 47 through which is engaged a screw 48, and which screw is driven intothe wall 10 of t-heform. The lower end of the rod 46 is reduced in diameter, where it passes through the brace 44, and disposed'in encircling relation to this portion of the rod isa coil spring 49, the upper end of which engages with the shoulder 50, of the rod, and the lower end of which bears against thewasher 51, on-thc lower end of the rod, above the winged nut Disposed slidably and transversely through the vupper end of the rod 46 is a pin 53 which is'arranged to rest on the upper face of the brace 16, when the skeleton frame is properly seated in the form, and clamped thereon by turning the nut 52. The spring 49 urges the rod upwardly to release the pin from said brace, upon loose'nin'grthe niit thereby obviating lifting includes a frame 33, in which is supported a shaft 34, having a cutter 35 mounted thereon, and driven by the flexible shaft 36. Depending from the frame 33 is a projection or lug37, which is adapted to rest against the outer peripheral face of the form, to maintain the cutter in engagement with the upper face of the frame, which lies in the channel 13. Owing to the fact that the upper edges of the form incline downwardly and outwardly, the frame of the planer will lie in a corresponding plane, whereby the cutter will move in said plane so as to remove the proper amount from the upper edge of the frame, and thereby produce the required bevel thereof, for receiving thereon the correspondingly inclined edge portion of the upper face of the sounding-board, and thereby permit the proper and even gluing of the sound-board to said beveled edge.

After having formed the proper bevel on the upper edge of the skeleton frame, it is necessary to form transverse grooves 31 in the. upper edge of the frame, for receiving the end portions of the ribs of the sounding-board. To do this a tool is used, such as is illustrated in Figures 11 and 12. This tool includes a frame 39, to the lower face of which are adjustably connected the guiding plates 40, said plates being arranged to travel in the channels or grooves 31 of the form, the operator moving the frame of the tool longitudinally in said grooves, so that the cutter 39 will cut grooves transversely in the. upper beveled face of the skeleton frame. This tool cuts the grooves in such a way that the bottom walls of the grooves will be in planes parallel with the upper beveled face of the skeleton frame, whereby the end portions of the ribs of the sounding-board will more properly it therein, while the edge of the board properly and evenly rests on'the beveled face of the skeleton frame.

By means of these. tools the required bevel can be formed on the upper edge of the skeleton frame to properly receive the edge of the sounding-board, thereon and also to form the proper grooves transversely in said beveled edge to receive the portions of the ribs of the sounding-board. Heretofore this has been done by hand tools, such as planes and Chisels, but with the present tools this work can be done with the proper accuracy to permit the sounding-board being glued into firm contact with the skeleton frame atevery portion of its rim.

Strips 11 of various thicknesses, are

adapted to be placed inthe channel of the form so that the skeleton frame may be elevated to the proper degree for action by the planer and grooving tools.

To prevent play of the brace 16 toward and away from the wall 12, of the form,

suitable spacing "blocks 5% are placed between the wall and the adjacent vertical edge face of the brace.

Carried by each of the blocks 21 is a depending pin 55, which is arranged to enter a socket 56, in the block 22, to 1)1O]')(-)lfly position the wall E20, and to insure the proper engagement of the bolts 23 in the grooves 2 and iVhat is claimed is:

1. A device for treating the skeleton frame of a grand piano comprising a form adapted to receive the skeleton frame and including an inner wall and an outer wall,

the upper faces of the walls being inclined downwardly and outwardly of the form, "he inner wall being of a greater height than the outer wall and having openings receiving the braces of the skeleton frame.

2. A device for treating the skeleton frame of a grand piano comprising a channeled form adapted to receive the skeleton frame and including an inner wall and an outer wall, the upperfaces of the walls be ing grooved and inclined downwardly and outwardly of the form in a common plane for supporting a planing tool, the inner wall being of a greater height than the outer wall and having openings for receiving the braces of the skeleton frame.

3. A device for treating the skeleton frame of a grand piano comprising a channeled form adapted to receive the skeleton frame and having inner and outer walls the upper faces of which are transversely grooved for passage of a frame grooving tool, the inner wall being higher than the outer wall, and a portion of the inner wall being removable.

4. A device for treating the skeleton frame of a grand piano comprising a longitudinally channeled form having inner and outer walls adapted to receive the frame therebetween, said walls having their upper faces downwardly and outwardly beveled in a common plane for supporting a planing tool, and being transversely grooved to receive and guide a tool for forming sounding-board-rib receiving grooves in the frame, the inner wall having openings to receive portion of the braces of the frame and having a removable portion.

5. A device for supporting the skeleton frame of. a grand piano while beveling and transversely grooving the same comprising a walled form of a contour corresponding to that of the skeleton frame and adapted to receive the latter, the upper faces of the walls of said form being disposed in a common plane inclining downwardly and out wardly and having transverse grooves therein, in combination with a grooving tool adapted to be moved through the said grooves and supported on said walls to cut grooves in the upper face of the skeleton ill) frame, and having guiding means engaged in said form grooves.

6. A device for treating the skeleton frame of a grand piano comprising a longitudinally channeled form the inner walls of which are slightly higher than the outer walls, said inner walls and outer walls being transversely grooved, said form including a transverse channeled member for re ceiving the transverse brace of the frame, one wall of said transverse channeled member being removable and arranged to lie above the transverse brace, means for releasably holding said wall engaged with the form, and means for supporting the intermediate portion of said wall.

7 A device for supporting the skeleton frame of a grand piano while beveling and transversely grooving the same comprising a longitudinally channeled form of a contour corresponding to that of the skeleton frame and adapted to receive the latter, the upper faces of the side walls of said form being disposed in a common plane inclining downwardly and outwardly and having transverse grooves therein, the bottom walls of said grooves being in parallel relation to said upper faces, in combination with a' grooving tool adapted to be moved through the said grooves to cut transverse grooves T in the upper face of the skeleton frame, and havmg means guided m said grooves.

In testimony whereof, I affix my signature.

JAMES H. WILLIAMS. 

